ci: configure Dependabot for all relevant upgrades (#4337)

Author: erikgb

.github/dependabot.yml

@@ -1,7 +1,27 @@
 version: 2
 updates:
+  # Maintain dependencies for frontend
+  - package-ecosystem: "npm"
+    directory: "/"
+    schedule:
+      interval: "daily"
+  # Maintain dependencies for backend
+  - package-ecosystem: "gomod"
+    directory: "/"
+    schedule:
+      interval: "daily"
+  # Maintain dependencies for website
+  - package-ecosystem: "npm"
+    directory: "/website"
+    schedule:
+      interval: "daily"
   # maintain dependencies for github actions
   - package-ecosystem: "github-actions"
     directory: "/"
     schedule:
       interval: "daily"
+  # maintain dependencies for Dockerfiles
+  - package-ecosystem: "docker"
+    directory: "/"
+    schedule:
+      interval: "daily"